The characteristics of gas adsorption of chemical treated natural zeolite from Kampo area in Korea was investigated. Acidl treatment was more effective than alkali treatment because exchanged $H^+$ ion was attributed to enlargement of pore size. In HCI treatment, 80% of pore area was derived from higher portion of micropores and lead to hindrance to gas diffusion. Though the pore and surface area decreased in NaOH treatment, increase of gas adsorption amount was found and it could be supposed that exchanged N$a^+$ ion located on surface served and adsorption site and induced better performance. The NaOH treated natural zeolite showed higher value of adsorption amount than the HCI treated.